Role of steroids in croup and beta agonists in bronchiolitis

The administration of corticosteroids by various routes in the treatment of croup remains controversial as studies with varying designs and outcome measures have reported conflicting results. However, meta-analysis supports the use of steroids in croup. A dose equivalent to or greater than 100 mg/kg body weight of hydrocortisone, administered orally or parenterally appears to be effective. Nebulized budesonide in a dose of 1,000 micrograms, when dosages are given 30 minutes apart is also effective. The L-epinephrine is as effective as racemic epinephrine and should be used to relieve symptoms with or without steroids. Summarizing the value of beta agonists, for treatment of bronchiolitis is rather challenging. Beta agonists offer significant relief to only a subgroup of infants, with bronchiolitis, albeit, it remains a challenge to identify these infants prospectively. Availability of RSV immune globulin for prevention of RSV disease in highrisk infants and better defining the role of ribavirin for selected patients may offer additional avenues to the treating physician.     

A prospective randomized study to determine the efficacy of steroids in treatment of croup.

We evaluated the use of dexamethasone in the management of acute laryngotracheobronchitis (croup). Thirty patients, ranging in age from eight to 60 months, were evaluated in a prospective, double-blind study. Patients received dexamethasone, 0.3 mg/kg at the time of admission and a similar dose 2 hours later, and were compared with a placebo group receiving saline. Sixteen patients received dexamethasone and 14 patients received the placebo. Severity of each group was scored by a standardized system. Patients receiving dexamethasone had a mean admission score of 8.46 points; patients receiving placebo, 8.14. Twenty-four hours after admission the patients in the treatment group had a mean score of 1.19 as contrasted with a score of 5.58 for the placebo group (P less than 0.01). We concluded that dexamethasone when administered in adequate dosage by an intramuscular route hastens the recovery of infants and children with acute uncomplicated croup.     

Repeated dose inhaled budesonide versus placebo in the treatment of croup

OBJECTIVE: To investigate the efficacy and tolerance of 12-hourly dosing with 2 mg 4 mL-1 of inhaled budesonide versus placebo in patients admitted to hospital with moderate/severe croup. METHOD: Eighty-two children hospitalised with croup received either 2 mg 4 mL-1 of budesonide or placebo 12 hourly (maximum four doses) via Ventstream nebuliser in a randomised, double-blind manner. Croup scores were performed at 0, 2, 6, 12, 24, 36 and 48 h from initial nebulisation whilst the patient remained hospitalised. Follow-up assessments were made 1 and 3 days after discharge. RESULTS: Improvement was observed in the budesonide group over the 12-h dosing interval when compared to placebo (P = 0.04). Time to attain a significant clinical improvement was superior in the budesonide group (P = 0.01). Three days after discharge seven of 32 placebo-treated patients and one of 34 budesonide-treated patients had sought further medical follow-up (P = 0.02). CONCLUSION: Twelve-hourly dosing with inhaled budesonide significantly improved symptoms of croup as well as decreased relapse rates when compared with placebo.     

Role of parainfluenza virus-specific IgE in pathogenesis of croup and wheezing subsequent to infection

In order to determine the role of parainfluenza virus-specific IgE antibody production and release of histamine in the pathogenesis of lower respiratory disease caused by parainfluenza virus infection, we studied 84 infants and children at the time of parainfluenza virus infection. Parainfluenza virus-IgE antibody was detected in samples of nasopharyngeal secretions by means of an enzyme-linked immunosorbent assay, and histamine content of nasopharyngeal secretions was determined by a fluorometric technique. Virus-specific IgE responses appeared earlier and were of greater magnitude in patients with croup, wheezing, and croup with wheezing caused by parainfluenza virus infection than in patients with parainfluenza virus-induced upper respiratory illness. Histamine was detectable in nasopharyngeal secretions of patients with parainfluenza virus-related croup significantly more often than in patients with upper respiratory illness caused by parainfluenza virus. These observations suggest a role for immunologic mechanisms in the pathogenesis of severe forms of respiratory illness caused by parainfluenza virus infection.     

Recurrent croup.

Thirty one of 486 children followed from birth had recurrent croup in the first four years of life. Twenty one were boys, and 10 girls. Recurrent croup occurred significantly more often in families with a positive history of allergy but was not significantly associated with the initial feeding method.     

Pseudomembranous croup.

During a 2-year period, 7 children were seen with a severe form of laryngotracheobronchitis associated with sloughing of the respiratory epithelium and profuse mucopurulent secretions. We have called this condition pseudomembranous croup. The children had severe upper airways obstruction, appeared toxic with high fever, and were older than the typical age group for viral laryngotracheobronchitis. Lateral x-ray films of the airways showed subglottic narrowing and often these suggested the presence of radio-opaque foreign material in the tracheal lumen. At endoscopy, in addition to pseudomembrane in the subglottic region and trachea, there was thick mucopus and debris, and in some cases these changes extended into the bronchi. An artificial airway was required in all except one, and even after intubation it proved difficult to maintain the airway. Staphylococcus aureus was the most common pathogen isolated from tracheal cultures but other organisms were grown.     

Childhood croup]

Hoarseness, whooping cough and stridor are elements of a syndrome of upper airway obstruction. In childhood, acute laryngotracheobronchitis is by far the commonest cause of this syndrome. Yet, the differential diagnosis includes a number of rare and severe entities. In many cases, the traditional distinction between viral and spasmodic types is not possible. The value of humidifying therapy has not been established. In severe cases, nebulized adrenaline is of benefit but should be reserved for hospital. The effect lasts only two hours and at times a rebound effect is observed. It is now realized that some patients treated with adrenaline can safely be discharged after a two to three hours observation. There is a large body of evidence that all children arriving at the emergency department with croup should receive steroids without delay. This policy results in a much better outcome, with important reduction in hospitalizations, intensive care unit admissions and incubations. Oral dexamethasone is the drug of choice: it is as effective, easier to administer and cheaper than nebulised budesonide. In most studies, dexamethasone has been used at a dose of 0.6 mg/kg but there is some evidence that 0.15 mg/kg may be just as effective.